<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>hello vue</title>
</head>
<style>
    .active {
        color: red;
    }
</style>
<body>
    <div id="app">
        <h2 class="active">{{message}}</h2>
        <h2 :class="active">{{message}}</h2>

        <!-- <h2 v-bind:class="{key1: value1, key2: value2}">{{message}}</h2>
        <h2 v-bind:class="{类名1: true, 类名2: boolean}">{{message}}</h2> -->
        <h2 class="title" v-bind:class="{active: isActive, line: isLine}">{{message}}</h2>
        <h2 class="title" v-bind:class="getClasses()">{{message}}</h2>
        <button v-on:click="btnClick">按钮</button>
    </div>
    <script src="../js/vue.js"></script>
    <script>
        
        const app = new Vue({
            el: '#app',    
            data: {    
                message: '你好啊',
                active: 'active',
                isActive: true,
                isLine: true
            },
            methods: {
                btnClick: function () {
                    this.isActive = !this.isActive;
                },
                getClasses: function () {
                    return {active: this.isActive, line: this.isLine}
                }
            }
            
        })
    </script>
</body>
</html>